Thermostatic auxiliary fire-alarm system



No. 6l6,082. Patented D80. 20, I898. A. H. CROSS.

THERIOSTATIC AUXILIARY FIRE ALARM SYSTEM.

(Application filed June 1, 1898.)

(No Model.)

THE uozms arms so. morroumoq WASMINGTON. n. c.

UNITED STATES PATENT OFFICE.

ALBERT H. CROSS, OF NEW YORK, N. Y., ASSIGNOR TO THE GAHEIVELL AUXILIARYFIRE ALARM COMPANY, OF BOSTON, MASSACHUSETTS.

THERMOSTATIC AUXILIARY FIRE-ALARM SYSTEM,

SPECIFICATION forming part of Letters Patent No. 616,082, dated December20, 1898. Application filed June 1, 1898. Serial No. 682,241. (Nomodel.)

To (I/U/ whom it may concern:

Be itknown that I, ALBERT H. CRoss, a citizen of the United States,residing at New York city, in the county and State of New York, haveinvented a certain new and useful Improvement in Thermostatic AuxiliaryFire- Alarm Systems, of which the following is a specification.

My invention relates to various new and useful improvements in auxiliaryfire-alarm systems which will operate to automatically trip or otherwiseactuate the starting or controlling mechanism of a street-box to send inan alarm, but which may also be provided with means by which thestreet-box may be manually operated from one or more points on theauxiliary circuit.

In carrying out my invention I provide a suitable thermostatic orcompound wire which is included in the auxiliary circuit and which isextended throughout the dwelling, warehouse, or other building to beprotected, but being preferably exposed as much as possible, so as to besubjected to any fire which may be started. This wire may be of anywell-known construction; but preferably it comprises a compoundconductor consisting, first, of a copper core; second, a layer of afusible metal surrounding said core; third, a layer of insulation,preferably textile in character, surrounding the fusible wire; fourth, aplurality of conductors generally arranged spirally around the outsideof such insulation, and, finally, an outer sheathing of any suitablecharacter. The layer of insulating material between the fusible metaland the plurality of conductors is of a textile charactor, as explained,so that under the eifect of heat the fusible metal may melt andpercolate through the interstices of such insulating layer toshort-circuit the interior conducting-core and one or more of the outerconductors.

In its simplest form my invention will comprise a suitable thermostaticor compound wire directly included in an open-circuit auxiliary systemand arranged throughout the building to be protected, whereby upon thestarting of a fire the heat thereof will melt the fusible metal,short-circuiting the two conductors, thereby bridging the auxiliary witha compound or thermostatic wire a third wire made of fusible metal andwhich will be extended throughout the building, preferably parallel withthe compound wire, the third wire being normally closed in the auxiliarycircuit on a small gravity-battery insufficient to actuate thestreet-box. One conductor of the compound wire in a closed-circuitsystem is connected with one pole of the main battery, the other pole ofwhich is connected to one side of the auxiliary system, and the otherconductor or conductors of the compound wire being connected to theother side of the auxiliary system. Suitably-arranged manually-operatedswitches are provided which normally complete the circuit through thethird wire to maintain the auxiliary circuit closed through thegravity-battery, but each of which is adapted to make contact withcontact-plates connected to the same conductor of the compound wire asthe main battery. In this way the street-box can be tripped from theauxiliary system by operating any one of the switches to first break thecircuit through the third wire and to then complete the circuit throughthe main battery and a part of the compound wire, as will be explained,In the event of a fire the third or fusible wire will first be melted tobreak the circuit at that point, and the heat will then cause thefusible metal of the compound wire to melt and percolate through thetextile insulating layer to short-circuit the two conductors thereof,throwing the main battery into the auxiliary circuit and operatingautomatically the street-box. By means of myinvention, therefore, itwill be seen that provision is made by which an alarm may beautomatically transmitted to the street-box by a fire occurring in anyroom or at any point of the building or dwelling instead of atfrequently remote and isolated points, as is the case when separatethermostats are employed.

It will furthermore be seen that by means of my invention allthermostatic contacts are dispensed with, which have heretofore been asource of objection, as they become corroded and covered with dust andfrequently fail to operate.

Finally, my invention is of advantage in that the street-box isautomatically operated only in the event of a very material rise intemperature, whereas with thermostats as now constructed they are liableto operate at temperatures which are well within the safety limits.

In the accompanying drawings, Figure 1 illustrates, diagrammatically, mypresent improvements applied to a simple type of closedcircuit auxiliaryfire-alarm apparatus; and Fig. 2 is a cross-section, on an enlargedscale, of the preferred form of thermostatic or compound wire employed.

Referring first to Fig. 2, 1 represents an electrical conductor, aroundwhich is placed a layer or coating 2 of asuitable fusible metal. 3 is aninsulated layer, made, preferably, of textile material, and t a aresmall conductin g-wires which are preferably spirally wound upon thelatter. The entire cable is covered by a sheathing 5 of insulatingmaterial and of any suitable character. Compound or thermostatic wire ofthe type referred to is a wellknown article of manufacture, and I do notclaim the same per 36.

Referring to Fig. 1, l3 0 represent the wires of an auxiliary circuit onthe outside of a building, extending to a street-box 7, the saidauxiliary eircuitincluding a magnet 8 or other mechanism for tripping,starting, or controlling the box. 9 is a third wire, made of suitablefusible metal,eitlier bare or insulated,and extended throughout therooms or through the exposed portions of a dwelling,warehouse, or otherbuilding. This wire normally closes the auxiliary circuit (3 (3 througha small gravity-battery 9, which is insufiicient to start the box, butwhich may be employed for the usual testing purposes or for indicatingin any suitable and approved way any derangements in the auxiliarycircuit within or outside of the building, as I shall describe. In thecircuit 0 may be placed one or more switches 10 within suitableauxiliary boxes, which switches are adapted to be pulled by a ring 11,as is now common, the said switch passing in its movement from thecontactplate 12 of the circuit 9 to the contact-plate 123. The switch inpassing between these contact-plates may make contact with a third platewhen it is desired to effect a return-signal at the auxiliary box, as isnow common with systems of this kind.

In Fig. 1 the compound thermostatic wire is illustrated generally at 14,the two condu ctors being designated, respectively, 15 and 16 and beingdistinguished by lines of dif ferent thicknesses. This compound orthermostatic wire is extended throughout the building parallel with thefusible wire 9 and preferably close to the same. If desired, the fusiblewire 9 may be wrappedloosely around the compound wire, or it maybeotherwise secured to the same. The conductor 15 is connected by a wire17 to one pole of the main battery 18, the other pole of that batterybeing in series with the gravity-battery 9 through a wire 19. The otherconductor 16 of the compound or thermostatic wire is connected to thestreet-wire U of the auxiliary circuit. The plates 1-) are connected bywires with the conduetorli of the compound or thermostatic wire.

The operation of my improved auxiliary fire-alarm system is as follows:Normally the circuit extends from the streetbox, wire (5,gravity-battery 9, wire O,contact-1' lates 12, switch-arms 10, and wire(3 back to the box, including the starting-magnet S or other device. Thecurrent of the battery 9 will hence constantly affect the line and maybe employed in any well-known way for test purposes or for indicatingbreaks or derangemcnts therein. \Vhen an alarm is to be sent in manuallyat any auxiliary box, the ring 11 will be pulled, moving one of theswitcharms 10 from the plate 12, breaking the circuit 9, and closing thecircuit through the main battery through the plate 13, the circuitthrough the main battery therefore extending from the box, wire (3,gravity-bat tery 9, wire 19, main battery 18, wire 17, conductor 15,plate 13, switch-arm 10, and street -wire 6 back to the box. The currentof the main battery will be sufficient to trip the box in any suitableway to send in the alarm. In the event of fire or an abnormal rise intemperature the fusible wire will first be ruptured by the heat,operating in the same way as by the breaking of that circuit by movingthe switch-arm 10 from the contact-plate 12. The fusible metal 2 in thecompound wire will also melt, and, percolating through the intersticesof the insulated layer 8, will short-circuit the conductors 15 and 16,so that the main battery will be thrown into the circuit with the box toactuate the same. This circuit, it will be noted, will extend from thebox 7, street-wire l3, gravity-battery 9', wire 19, main battery 18,wire 17, conductor 15, across the bridge formed by the melting of thefusible metal to the conductor 16, and street-wire 6 back to the box.

In the Gamewell auxiliary lire-alarm system, with which my invention isadapted for use, the auxiliary circuit is arranged to be broken at thestreet-box immediately after the box commences to operate, in order thata return-signal may be transmitted to the auxiliary box and the operatorthereat may know that. the signal has been received and is beingtransmitted by the street-box. After the street-box has sent in thesignal, however,

the auxiliary circuit is reestablished, and when the tripping-magnet 8has been reset the auxiliary circuit is ready for further operation.Incasetheauxiliaryeircnithasbeen manually operated the return of theswitches 10 to close the circuit 9 through the gravitybattery willenable the operating-magnet 8 at the street-box to be reset. When,however, the auxiliary circuit has been actuated automatically by afire, the circuit through the main battery will be maintained closedbetween the conductors and 16 and it will be impossible to reset themagnet 8, or if that magnet were reset the street-box would be againimmediately operated. lVith this type of apparatus, therefore, I makeuse of a relay 20 which is included in the circuit 9 in each auxiliarysystem-as, for example, between the gravity-battery 9 and the wire 19.The relay 20 is provided with an armature 21, pivoted at 22, which maymake contact with a back stop 23 to close a local circuit through a bell24-.

is a support carried by the yoke of the relay-magnet, and 26 is a leverpivoted in said yoke, the lower end of said lever working between thetwo coils of the relay. The said lever carries an insulated stud 27,mounted on an adjusting-screw 28, which stud forms a front stop for thearmature 21. A lockinglever 29 is pivoted on the support and is normallyelevated by a spring 30, coiled around its pivot. The said locking-levercarries a stud 31 at its forward end, which engages in a notch 32 in thelever 26, so as to lock said lever in the normal position shown.

33 is a heavy spring-contact, and 34 a light spring'contaet, insulatedfrom each other at their rear ends, but normally making contact at theirforward ends through the two contact-pieces 35, as shown. Thespring-contacts 33 and 34 are normally maintained in engagem cut bymeans of a pin 86, carried on the lever 26, near its lower end. The saidspring-contacts 33 and at are in series with the coils of therelay-magnet and the conductor 9.

By the use of a relay arranged as shown it will. be observed that thenormal closure of the circuit 9 through the gravity-battery willenergize the relay suiiiciently to maintain its armature in contact withthe insulated front stop 27, breaking the local circuit through the hell24. If, however, this circuit becomes accidentally broken or otherwisederanged, so as to deenergize the relay 20, the armature 21 will beengaged with the back stop 23 to close the circuit through said bell andthereby give a notification of this fact.

In operating the auxiliary system the closure of the circuit through themain battery will, in addition to tripping the street-box, energize therelay 2O sufficiently to cause its armature to trip the lever 26 fromthe latch 29, said latch therefore moving upwardly on its pivot. Thismovement will not break the circuit between the spring-contacts 33 and34-, as will be obvious. When, however, the

circuit is broken at the street-box, the relay 20 will be deenergized,allowing the armature 21 to be retracted, whereupon the springcontactsand 34. will separate to break the auxiliary circuit at that point, andthe said auxiliary circuit will not be reestablished until thespring-contacts 33 and 34: have been again engaged, and are held in thisposition by the locking of the lever 26 by means of the locking-lever29. It will thus be seen that when the auxiliary circuit is operatedautomatically and the conductors 15 and 16 are short-circuited, theauxiliary circuit will be broken at the relay 20, so as to allow theauxiliary magnet of the street-box to be reset, after which the fusedsection or sections of the auxiliary circuit may be repaired and thecircuit put in condition for further use.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. In an auxiliary fire-alarm system, the combination with a street-box,of a normallyclosed auxiliary circuit including a section of fusiblewire extending throughout a building, and a compound or thermostaticwire arranged parallel to said fusible wire and normally disconnectedfrom the auxiliary circuit, substantially as set forth.

2. In an auxiliary fire-alarm system, the combination with a street-box,of a normallyclosed auxiliary circuit including a section of fusiblewire extending throughout a building, a compound or thermostatic wirearranged parallel to said fusible wire and normally disconnected fromthe auxiliary circuit, and a main battery connected to said thermostaticor compound wire, substantially as set forth.

In an auxiliary fire-alarm system, the combination with a street-box, ofa normallyclosed auxiliary circuit in which is included a section offusible Wire, a manually-operated switch for breaking the circuit ofsaid fusible wire, a compound or thermostatic wire arranged parallelWith the fusible wire and normally disconnected from the auxiliarycircuit, and a contact-plate with which said switch may make contactconnected to said compound wire, substantially as set forth.

4. In an auxiliary fire-alarm system, the combination with a street-box,of a normallyclosed auxiliary circuit in which is included a section offusible wire, a manually-open ated switch for breaking the circuit ofsaid fusible wire,a compound or thermostatic wire arranged parallel withthe fusible wire and normally disconnected from the auxiliary circuit, acontact-plate with which said switch may make contact connected to saidcompound wire, and a main battery connected to said compound wire,substantially as set forth.

5. In an auxiliary lire-alarm system, the combination with a street-box,of a normallyclosed auxiliary circuit including a section of fusiblewire extending through a building, a

compound or thermostatic wire arranged parallel to said fusible wire andnormally disconnected from the auxiliary circuit, anda relay in theauxiliary circuit controlling a local circnit in which is included asignaling device,

substantially as set forth.

0. In a normally-closed auxiliary lire-alarm system wherein theauxiliary circuit is broken at the street-box after the latter hasstarted, the combination with a street-box, of a normally-closedauxiliary circuit including a section of fusible wire extendingthroughout a building, a compound or thermostatic wire ar 'angedparallel to said fusible wire and normally disconnected from theanxiliarycircuit, a main battery connected to said thermostatic orcompound wire, a relay in the aux iliary circuit, and a circuit-breakingdevice in the auxiliary circuit controlled by said re- 5 lay,substantially as set forth.

7. In a normally-closed auxiliaryfire-alarm system wherein the auxiliarycircuitis broken at the street-box after the latter has started, thecombination with a street-box, of a norin ally-closed auxiliary circuitincluding a seci tion of fusible wire extending throughout a i building,a compound or thermostatic wire 5 arranged parallel to said fusible wireand norl nially disconnected from the auxiliary circuit, {a main batteryconnected to said thermo- 1 static or compound wire, a relay in theauxiliary circuit, a circuit-breaking device ini cluded in the auxiliarycircuit, and a tripping device controlled by said relay for breaking ithe auxiliary circuit at the relay when the l auxiliary circuit isbroken at the street-box, l substantially as set forth. I Thisspecification signed and witnessed this 1 27th day of May, 1898.

ALBERT ll. CROSS.

\Yitnesses:

Jxo. R. Txxjnon, Fnxxx Tl. Dxnn.

